Derivation Gap identified in LLM tool-call verification
October 12, 2026
A study of seven LLM judges reveals a derivation gap where models fail to accept correct tool-call arguments if the reference text is missing or inferred. This failure occurs even when values are correct defaults from a function schema.
HOW THIS AFFECTS YOU
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builderYou must ensure your evaluation prompts explicitly include all necessary context to avoid false negatives in agent testing.
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researcherThis highlights a systemic weakness in how LLM judges handle implicit reasoning in tool-use benchmarks.